Trouble Shooting

Calculations on some pages are dependent on other data file(s) being loaded. In this case, WAITE FOR THE PAGE TO BE FULLY LOADED. Otherwise, calculation may be terminated and error message may appear.

Drain - Horizontals and Stacks

Building Drain Sizing
SlopeDFURecommended Size
Max DFUMargin

How to Use:

  1. Select slope. The default is (1"/8' or 1:96).
  2. Enter DFU.
  3. The recommended building drain size will show on the right.
  4. The maximum DFU that the recommended size can take and the margin, or safety factor, will also show.
  5. Note: Since slopes are dependent on diameter, e.g., if d<4", the minimum slope shall be 1"/4' (or 1/4 inch per foot). Therefore, when you select slope as 1"/8',no matter how small the DFU you entered is , the recommended pipe size will be 4". On the othe hand, flow from small DFU may not be fast enough reach th self-cleaning velocity. Thus, you may have to chose a smaller diameter.
  6. Refer to plumbing code applicable to your project for minimum slope of a given size drain.
Branches Connecting to Stacks DFURecommended Drain Size (inch)Max DFUMargin

Warning! The above calculators are for your convenience only. Be sure to check your local plumbing code in use.

Stack Sizing
Stack intervalsDFURecommended Drain Size (inch)Max DFUMargin

PlumAL can do more:

More Reading:

Return to Main Menu
Product Selection